In JavaScript, the Map.prototype.keys
method is used to get an iterator object that contains the keys of a Map. The iterator object follows the iterable protocol, allowing you to loop through the keys using methods like next()
or using a for...of
loop.
Syntax:
myMaps.key();
-
myMap
: The Map for which you want to obtain an iterator for its keys.
Example: Below is an example of a key method in a map.
Javascript
let myMap = new Map();
myMap.set( 'key1' , 'value1' );
myMap.set( 'key2' , 'value2' );
myMap.set( 'key3' , 'value3' );
// Get an iterator for the keys of the Map let keysIterator = myMap.keys(); // Use the iterator to loop through the keys let nextKey = keysIterator.next(); while (!nextKey.done) {
console.log(nextKey.value);
nextKey = keysIterator.next();
} |
Output
key1 key2 key3